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31.
Umbilical cord blood of newborns and peripheral blood of healthy adults were investigated by an immunospot assay for cells secreting IgG, IgA and IgM antibodies against myelin basic protein (MBP), proteolipid protein (PLP), myelin-associated glycoprotein (MAG) and myelin oligodendrocyte glycoprotein (MOG) which represent putative antigens for an autoimmune attack in multiple sclerosis (MS) and against acetylcholine receptor (AChR) which is considered an important autoantigen in myasthenia gravis. Cells secreting antibodies against one or more of these autoantigens were detected in 18 out of 24 newborns, and in eight out of 20 adults. Eight of the cord blood samples contained cells secreting antibodies of IgG, IgA and/or IgM isotypes to one antigen, five to two antigens, two to three antigens, two to four antigens, and one to five antigens. Most prominent were anti-MBP IgG antibody secreting cells which were detected in 13 newborns at a mean number of 1/20,000 cord blood cells, and in six adults at a mean number of 1/10(5) peripheral blood cells. Anti-AChR IgG antibody secreting cells were detected in four out of 12 newborns versus four out of 14 peripheral blood specimens, at mean values of 1/10(5) cells in both instances. Cells secreting autoantibodies of IgA and IgM isotypes were less frequent both in cord blood and peripheral blood. The occurrence of nervous tissue autoantibody secreting cells in newborns must be related to a possible primary role of such autoantibodies in MS and myasthenia gravis.  相似文献   
32.
Myelin basic protein (MBP)-reactive T cells are thought to play an important role in the pathogenesis of multiple sclerosis (MS). In some patients with MS, these autoreactive T cells display a limited heterogeneity in their epitope recognition and T cell receptor (TCR) variable (V) gene usage. These individual-dependent properties of MBP-reactive T cells have led to the speculation that they may represent clonal expansion in vivo in some MS patients. In the present study, 51 MBP-reactive T cell clones derived from patients with MS and healthy individuals were examined for their epitope recognition and the TCR Vα and Vβ gene rearrangements. The V gene junctional region sequences of identified α and β genes were further analyzed to probe their clonal origins, as the sequences are unique for individual clones. Our data showed that 26 clones derived from nine patients with MS shared a predominant reactivity to the immunodominant regions of MBP, 84–102, 110–129 and 143–168, and used various TCR Vα and Vβ rearrangements. The V gene usage of the clones was restricted to certain Vα Vβ combination(s) in a given MS patient, but varied among different patients. The sequence analysis revealed that the clones generated from a given patient shared a limited or a single junctional region sequence pattern(s), indicating their oligoclonal or monoclonal origin(s). In contrast, 25 MBP-reactive T cell clones derived from normal individuals exhibited unfocused epitope recognition and V gene usage. Thus, the limited heterogeneity of MBP-reactive T cells in their structural and functional charactertistics reflects their clonal expansion in vivo in some patients with MS.  相似文献   
33.
To investigate the representation of motor sequence, we tested transfer effects in a motor sequence learning paradigm. We hypothesize that there are two sequence representations, effector independent and dependent. Further, we postulate that the effector independent representation is in visual/spatial coordinates, that the effector dependent representation is in motor coordinates, and that their time courses of acquisition during learning are different. Twelve subjects were tested in a modified 2x10 task. Subjects learned to press two keys (called a set) successively on a keypad in response to two lighted squares on a 3x3 display. The complete sequence to be learned was composed of ten such sets, called a hyperset. Training was given in the normal condition and sequence recall was assessed in the early, intermediate, and late stages in three conditions, normal, visual, and motor. In the visual condition, finger-keypad mapping was rotated 90 degrees while the keypad-display mapping was kept identical to normal. In the motor condition, the keypad-display mapping was also rotated 90 degrees, resulting in an identical finger-display mapping as in normal. Subjects formed two groups with each group using a different normal condition. One group learned the sequence in a standard keypad-hand setting and subsequently recalled the sequence using a rotated keypad-hand setting in the test conditions. The second group learned the sequence with a rotated keypad-hand setting and subsequently recalled the sequence with a standard keypad-hand setting in the test conditions. Response time (RT) and sequencing errors during recall were recorded. Although subjects committed more sequencing errors in both testing conditions, visual and motor, as compared to the normal condition, the errors were below chance level. Sequencing errors did not differ significantly between visual and motor conditions. Further, the sequence recall accuracy was over 70% even by the early stage when the subjects performed the sequence for the first time with the altered conditions, visual and motor. There were parallel improvements thereafter in all the conditions. These results of positive transfer of sequence knowledge across conditions that use dissimilar finger movements point to an effector independent sequence representation, possibly in visual/spatial coordinates. Initially the RTs were similar in the visual and the motor conditions, but with training RTs in the motor condition became significantly shorter than in the visual condition, as revealed by significant interaction for the testing stage and condition term in the repeated measures ANOVA. Moreover, using RTs for single key pressing in the three conditions as baseline indices, it was again observed that RTs in the visual and motor conditions were not significantly different in the early stage, but motor RTs became significantly shorter by the late testing stage. These results support the hypothesis that the motor condition benefits more than the visual because it uses identical effector movements to the normal condition. Further, these results argue for the existence of effector dependent sequence representation, in motor coordinates, which is acquired relatively slowly. The difference in the time course of learning of these two representations may account for the differential involvement of brain areas in early and late learning phases found in lesion and imaging studies.  相似文献   
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36.
GKT原理的模拟犯罪测试范式实验研究   总被引:2,自引:0,他引:2  
目的:本实验旨在以实际犯罪较接近的实验场景验证GKT的测谎机制,并探讨其对罪犯以及其他嫌疑人的判定有效性。方法:以72名健康大学生为被试,让被试在模拟犯罪的背景下采用三种包含不同说谎和认知成分的回答方式进行测谎测试,采用Limestone测谎仪测量被试皮肤电反应。结果:回答方式与角色两因子在判定分数上的主效应均显著,交互作用不显著。结论:在模拟犯罪测试范式下,GKT模式中认知与说谎机制是共存的,其中认知成分不占主要地位,说谎成分占主要地位,GKT模式无法兼顾有效地判定"犯罪"和"知情无辜"角色,需进一步改进。  相似文献   
37.
目的 探讨肝素酶(heparanase)和碱性成纤维细胞生长因子(bFGF)在人非小细胞肺癌(NSCLC)组织中表达的临床意义及其与肺癌转移和预后的关系。方法 采用免疫组织化学、原位杂交和Western blot方法,检测115例人NSCLC石蜡切片和45例新鲜肺癌及对应癌旁正常组织中肝素酶和bFGF的表达情况。采用χ^2检验、t检验、生存曲线和Cox比例风险回归等方法分析肝素酶和bFGF分别表达及共表达的意义。结果 免疫组织化学染色证实肝素酶(91/115)和bFGF(89/115)主要表达在癌细胞质和(或)细胞膜中,在正常肺泡上皮和支气管上皮中则呈阴性表达。Western blot也证实肝素酶在肺癌中的表达明显增高(P=0.041)。统计分析结果显示:肝素酶和bFGF的表达具有明显的一致性(P:0.0001),二者单独表达和共表达均与肺癌的分期、血管侵袭、淋巴结转移、微血管密度和预后有关,其中,二者共表达时与分期和微血管密度的相关性更显著;另外,bFGF还与肺癌的分化程度有关。多因素分析结果显示,肺癌的分化程度、血管浸润、淋巴结转移和bFGF的表达可以作为判断肺癌预后的危险因素,但肝素酶不是影响预后的独立因素。结论 肝素酶和bFGF均与肺癌的转移、血管生成和预后密切相关。  相似文献   
38.
以无形资产为切入点.探讨图书馆在网络环境下与各类信息源及用户的辩证关系;以人为本的知识资本运营.无形资产的投入和知识产权保护比以往更加重要;提出社会无形资产概念:甄别信息资源专有权与公有权.论证图书馆社会角色;辨析图书馆知识管理.无形资产评估、立法理念。  相似文献   
39.
Two types of inhibition of basic peptide-induced rat mast cell secretion are reported. Pretreatment of rat peritoneal mast cells with Vibrio comma neuraminidase, an enzyme which cleaves sialic acid from oligosaccharides, led to inhibition of 5-hydroxytryptamine release induced by the basic peptides polylysine, corticotropin1–24 and a decapeptide sequence of human IgE. Inhibition was similarly observed when mast cells were challenged in the presence of the cationic cell membrane-active substance benzalkonium chloride. It is postulated that both of these experimental procedures inhibit basic peptide-induced secretion by depletion of cell surface negative charge. Sialic acid itself does not act as a specific receptor for basic peptides, since a molar excess of sialic acid in free solution failed to inhibit secretion by binding to basic peptides in the fluid phase.  相似文献   
40.
Epitope spreading has been implicated in the pathogenesis of experimental autoimmune encephalomyelitis (EAE) and human multiple sclerosis (MS). T cell epitope spreading has been demonstrated in rodents for myelin basic protein (MBP) and proteolipid protein (PLP) determinants, but not for myelin oligodendrocyte glycoprotein (MOG), another important myelin antigen. Moreover, the role of human autoimmunity-associated MHC molecules in epitope spreading, including HLA-DR2 and DR4, has not been formally examined. To address these questions, we investigated epitope spreading to MOG determinants in HLA-DR4 (DRB1*0401) transgenic mice during EAE. The data show that upon induction of EAE in HLA-DR4 transgenic mice with the immunodominant HLA-DR4-restricted MOG peptide 97-108 (MOG(97-108); TCFFRDHSYQEE), the T cell response diversifies over time to MOG(181-200) (core: MOG(183-191); FVIVPVLGP) and MBP. The spreading epitope MOG(181-200) binds with high affinity to HLA-DRB1*0401 and is presented by human HLA-DRB1*0401+antigen presenting cells. Moreover, this epitope is encephalitogenic in HLA-DRB1*0401 transgenic mice. This study demonstrates intra- and intermolecular epitope spreading to MOG and MBP in "humanized" HLA-DR4 transgenic mice.  相似文献   
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